This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. The Odde lab (Univ. Minnesota) is interested in understanding the mitotic spindle in yeast at the level of interplay of motor function and microtubule dynamics such that the can mathematical model mitotic spindles. Their initial modeling work is presented in (Gardner M.K. et al. (2005) Tension-dependent regulation of microtubule dynamics at kinetochores can explain metaphase congression in yeast. Mol Biol Cell. 16:3764-3775.). To build this mathematical model they used previous 3D ultrastructural data on yeast mitotic spindles from the Boulder Laboratory (Winey, M., et al. (1995) Three-dimensional ultrastructural analysis of the Saccharomyces cerevisiae mitotic spindle. J. Cell Biol. 129:1601-1616.). To expand their modeling and to test the model by using it to predict the behavior of spindles in yeast strains mutant in various spindle components, Dave Odde has arranged a collaboration between his group (mathematical modeling) and that of Kerry Bloom (Univ. North Carolina - Chapel Hill, live-cell imaging) and Mark Winey and the Boulder Lab for the 3D Structure of Cells (EM tomography). Thus far, we have revisited wild-type spindle structure using tomography to confirm the previous results based on reconstruction from serial thin sections and to serve as controls for the analysis of mutants. We have also been collecting datasets and modeling spindles from a mutant strain lacking the CIN8 kinesin-like motor, which are very interesting. This work is proving very fruitful and may lead to a manuscript this year.